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On a $400,000 (400k) mortgage, modelled monthly repayments are about $2,528 over 30 years, or $2,701 over 25 years — modelled at 6.5%, as of 9 August 2026.
Modelled rate: 6.5% (indicative, as of 9 August 2026). This is not a lending offer, pre-approval or a rate guarantee — it matches the default in our Mortgage Calculator so the two pages agree. Actual rates vary by lender and your circumstances. Use the calculator below to re-run these numbers with your own quoted rate.
A shorter term means higher regular repayments but less total interest, because the balance is outstanding for less time. Both rows below use the same modelled 6.5% rate.
| Term | Weekly | Fortnightly | Monthly | Total interest |
|---|---|---|---|---|
| 25 years | $623 | $1,247 | $2,701 | $410,249 |
| 30 years | $583 | $1,167 | $2,528 | $510,178 |
Paying an extra $200 a month goes straight onto the principal, so it compounds — the loan is paid off sooner and every dollar of interest on the shortened tail is avoided entirely.
| Term | Standard monthly | With extra $200/mo | Interest saved | Time saved |
|---|---|---|---|---|
| 25 years | $2,701 | $2,901 | $70,537 | 3.8 years |
| 30 years | $2,528 | $2,728 | $110,794 | 5.6 years |
Change the rate, term, extra repayments and offset balance and see the full amortisation chart.
Modelled at 6.5% (as of 9 August 2026) over a 30-year term, a $400,000 mortgage costs about $2,528 a month — $1,167 fortnightly or $583 weekly. Over a 25-year term the monthly repayment rises to about $2,701 because the loan is paid off faster.
Over the full 30-year term, total interest on $400,000 at 6.5% comes to about $510,178 — more than half the original loan. Over 25 years total interest is lower, at about $410,249, because less time is spent accruing interest even though the monthly repayment is higher.
A 25-year term costs about $173 more a month but saves roughly $99,929 in total interest over the life of the loan. The right choice depends on what you can comfortably afford each month — most lenders will also let you make extra repayments on a 30-year loan to pay it off faster without committing to the higher minimum repayment.
These figures use a modelled, indicative rate of 6.5%, as of 9 August 2026 — matching the default in our Mortgage Calculator. It is not a lending offer, pre-approval or a guarantee that any lender will offer you this rate. Actual rates vary by lender, loan type, deposit size and your individual circumstances, and move over time, so use the calculator below with your own quoted rate for an accurate figure.
Paying an extra $200 a month on top of the standard 30-year repayment saves about $110,794 in interest and pays the loan off roughly 5.6 years early, without refinancing or changing your rate.
Lenders typically want your repayments to be a manageable share of your take-home income and stress-test you against a higher rate than you're actually paying. Use the Borrowing Power Calculator with your own income and expenses to see an estimate of what a lender might approve — this page only models the repayments on a loan of this size, not whether you would qualify for one.
We use the standard principal-and-interest amortisation formula, which spreads the loan amount plus interest evenly across every repayment over the term. It assumes the rate stays constant for the life of the loan, which is unrealistic for a variable-rate mortgage — the Mortgage Calculator lets you re-run the numbers whenever your rate changes.
Each page works through one loan amount in detail: repayments at 25 and 30-year terms, total interest, and what extra repayments save.
Estimates only. Not financial or tax advice. Full disclaimer for your rights and our limitations of liability.